Gilsonite is a solid hydrocarbon that forms a swarm of subparallel, northwest-trending, near-vertical, laterally and vertically extensive veins in the Uinta Basin of Utah and Colorado. The Uinta Basin hosts the worldâs largest deposits of gilsonite and is the only place where gilsonite is economically produced in large quantities.

The goal of the Utah Geological Survey study was to generate a map of the gilsonite veins, collect vein attribute data, and combine these new data with existing data into an up-to-date compilation of Utah's gilsonite resource. All of the data were compiled into a 1:100,000-scale geologic map and accompanying text, which includes detailed descriptions of the character of the gilsonite deposit for each vein, and evidence of mining and prospecting.